Most systems for providing three-dimensional pictures take the form of viewing means in which a paralax effect is provided. This paralax effect is achieved by providing two side-by-side pictures of the same scene but taken at slightly different angles and then channeling the respective pictures to a viewer's left and right eye as by a conventional stereoscopic viewer.
It is known, however, that three-dimensional effects from pictures can be realized by providing a relatively large screen which is curved in such a manner as to vary the optical light paths from various portions of the picture. The effect is striking for large scenes wherein the scenery itself, when viewed in real life, would not exhibit any appreciable paralax effect. In other words, beyond twenty feet or so, the paralax is simulating depth effects is substantially nil. The "cinerama" and "cinemascope" processes for motion pictures provide good examples of depth perception through the use of a large curved screen.
In the past, the foregoing depth effects have been practical only in relatively large motion picture houses or in situations where it is practical to provide a large curved screen upon which the picture is formed. More recently, large curved screens in combination with flat mirrors have been provided which are adaptable to smaller pictures or pictures projected from a projector onto a flat mirror and thence reflected to the curved screen. My U.S Pat. No. 3,246,943, issued Apr. 19, 1966, sets forth such a method and apparatus for image projection.
It would be desirable, however, to provide a simple viewing means for conventional flat pictures in which three-dimensional effects are realized without requiring direct curving of the picture itself or special mounting means therefor. Further, it would be desirable to provide such viewing means wherein the size of the picture itself is of small significance so that the system is adaptable to pictures of various different sizes such as conventional 3 .times. 5 snapshots or pictures of the type used in simple commercial display devices as in exhibits and the like, or even home television pictures.